Hey! I have always learned that functions like logarithms, exponentials, trigonometrics etc. have to operatore on pure numbers and not numbers with units. For instance, you cannot write: Sin ( 5 kg*m/s^2 ) But in chemistry I often find formulas where logarithmes of numbers with units are taken. If some of you happen to own Atkins - Physical Chemistry 8th edition you can look at page 807 and see what I mean. They take the logarithm of k and A which have units (the Arrhenius equation). How can you do something like that? Thanks!